Making contact by FM radio

[Bald Carl]

Any transmitter can be triangulated (DF'd). Simple measures can counteract this. Maintain radio silence (self defeating in a way) and keep radio transmissions to a minimum. Do not transmit for more than 20 secs so as to provide less of an opportunity to transmit your location.

Mobile phone operators use distance to base station calculations to determine locations for as long as the mobile is switched on.

Unless you are a major criminal, I wouldn't worry about things like this.